Women have made impressive advances in the workplace over the past two decades, but some critics claim sex discrimination is still rampant in such male-dominated industries as auto manufacturing.

The critics claim that a discriminatory "glass ceiling" prevents too many women from rising to leadership positions in companies including Ford, GM, and DaimlerChrysler. Does the auto industry really keep women from reaching the top of the corporate ladder?

It's true that only 7 percent of auto executives are women, but experts say women's choices including college major and time in the labor force largely account for their smaller numbers in executive positions.

For example, many more men than women choose to study engineering, which means that more men have the training necessary to advance in the auto industry. And many women choose to leave the workforce to spend time raising their children, voluntarily forgoing years of valuable experience.

Nevertheless, women are succeeding in corporate America. In 1973, women sat on only 11 percent of all corporate boards. In 1998, 72 percent of corporate boards had female members.

Women's progress in the workplace shows that if a glass ceiling ever did exist, women have long since shattered it.